Add ACCESS_NETWORK_STATE to Tethering CTS because tests call to
EthernetManager#isAvailable() which is enforcing permission check
now. Without ACCESS_NETWORK_STATE, some tests will fail by lack
of permission.
Bug: 174573778
Test: CtsTetheringTest
Change-Id: I735d98527c14c12fb0f2df536cda25fdd84152f1
Ignore-AOSP-First: Security vulnerability issue should not fix on
aosp branch.
90255ef0a7